Dehydration

What is dehydration?

Dehydration is when you don’t have enough water in your body. The human body normally contains a lot of water. It helps keep your body healthy and working well. Mild dehydration can cause problems with blood pressure, heart rate, and body temperature. Severe dehydration can also cause weakness or confusion. In extreme cases, it can lead to brain damage and even death.

Everyone loses body water daily through sweat, tears, breathing, urine, and stool. This water is replaced by drinking fluids and eating foods that contain water. Dehydration can have many causes. You may have lost water from sweating, diarrhea, or vomiting. Or you may be sweating from exercise or hot weather. Loss of water often leads to an imbalance of electrolytes in the body. Electrolytes are minerals and salts that the body needs to function. They include sodium, potassium, magnesium, and calcium.

What causes dehydration?

Dehydration can be caused by:

Sweating from hot weather, exercise, sauna use

Diarrhea

Vomiting

Fever

Some medicines that cause extra urination, such as diuretics

Who is at risk for dehydration?

You are more at risk if you:

Have diarrhea

Have vomiting

Are in hot weather

Are sweating a lot from exercise

Are an older adult age 60 or older

What are the symptoms of dehydration?

Symptoms can occur a bit differently in each person. They can include:

Thirst

Tiredness

Dizziness

Lightheadedness

Muscle cramps

Dry mouth

Less urine

Urine that’s more yellow or even light brown in color

Headache

Dry skin or tongue

Fainting

Confusion

Fast heart rate and breathing

The symptoms of dehydration can look like other health conditions. See your healthcare provider for a diagnosis.

How is dehydration diagnosed?

Your healthcare provider will ask about your symptoms and health history. The provider may also ask about recent illness or activity. He or she will give you a physical exam. Your blood pressure, temperature, and heart rate will be checked. You may have blood or urine tests.

How is dehydration treated?

Treatment will depend on your symptoms, your age, and your general health. It will also depend on how severe the condition is. You also may be treated for diarrhea, vomiting, or a high fever if illness caused your dehydration.

For moderate to severe dehydration, you may need IV (intravenous) fluids. Severe dehydration is a medical emergency. It needs to be treated right away with IV fluids in a hospital.

For mild dehydration, you can drink fluids. You may need to restore not just water, but also electrolytes such as sodium and potassium. Sports drinks can replace water and electrolytes. You can also drink water, fruit juices, tea, and soda.

Don't have drinks with caffeine. These include some energy drinks, teas, sodas, and coffee drinks. Don’t drink alcohol. Caffeine and alcohol may cause your body to lose more water.

Talk with your healthcare providers about the risks, benefits, and possible side effects of all treatments.

What are possible complications of dehydration?

Severe dehydration that is not treated can cause kidney damage, brain damage, and death.

What can I do to prevent dehydration?

Drink 12 8-ounce glasses of fluid every day. Drink more if you are in hot weather or exercising. Drinks may include:

Water

Fruit juices

Sports drinks. Be careful of the sugar in these drinks, especially if you have diabetes.

Other drinks that have electrolytes

Soda with no caffeine

Tea with no caffeine

Coffee with no caffeine

If you have been diagnosed with a kidney disease, ask your healthcare provider how much and what types of fluids you should drink to prevent dehydration. When you have kidney disease, fluid can build up in the body. This can be dangerous to your health.

When should I call my healthcare provider?

Call the healthcare provider if you have:

Diarrhea more than 5 times a day

Continued vomiting

Blood (red or black color) or mucus in diarrhea

Blood in vomit

Belly pain

Swollen belly

Fever of 100.4°F (38°C) or higher, or as directed by your healthcare provider